Outboard motor

ABSTRACT

An outboard motor can be mounted on a transom plate of a hull, and can have an engine disposed in an upright position in a cowling so that a crankshaft thereof extends generally vertically during cruising. A surge tank can be located on the hull side of the engine in the cowling, and a mounting portion for an electric component can be provided on a front face of the surge tank.

PRIORITY INFORMATION

This application is based on and claims priority to Japanese PatentApplication No. 2005-114817, filed Apr. 18, 2006, the entire contents ofwhich is hereby expressly incorporated by reference.

BACKGROUND OF THE INVENTIONS

1. Field of the Inventions

The present inventions relate to outboard motors, and more particularly,to outboard motors which have an engine disposed in an upright positionso that the crankshaft thereof extends generally vertically duringcruising.

2. Description of the Related Art

Outboard motors have long been known in the marine propulsion arts. Onecommonly used design is one in which the crankshaft of the engine in theoutboard motor extends generally vertically.

In more recent designs, a surge tank can be provided in an intakepassage of the engine located in front of the engine (the propeller sideis defined as the rear side). Additionally, an electric component suchas an engine control unit (ECU) can be mounted in front of the surgetank in the cowling. Such an outboard motor design is disclosed inJapanese Patent Document JP-A-Hei 9-88623.

SUMMARY OF THE INVENTIONS

An aspect of at least one of the inventions disclosed herein includesthe realization that in the outboard motor described in JP-A-Hei9-88623, there are constrains on the assembly because the electriccomponent must be attached after the intake manifold and the surge tankhave been connected because the electric component is attached to amember integrated with an intake manifold and the surge tank. Also,unless the electric component is removed, the surge tank or the intakemanifold cannot be removed since the electric component interferes withthe removal of them.

Thus, in accordance with at least one embodiment, an outboard motor cancomprise a cowling, an engine disposed in an upright position in thecowling such that a crankshaft of the engine thereof extends generallyvertically during cruising, a surge tank located on the hull side of theengine in the cowling, and a mounting portion for an electric componentprovided on a front face of the surge tank.

In accordance with at least another embodiment, an outboard motor cancomprise a cowling, an engine disposed in the cowling, a surge tanklocated on the hull side of the engine in the cowling, and a mountingportion configured to connect with an electric component provided on afront face of the surge tank

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features of the inventions disclosedherein are described below with reference to the drawings of thepreferred embodiments. The illustrated embodiments are intended toillustrate, but not to limit the inventions. The drawings contain thefollowing Figures.

FIG. 1 is a schematic side elevational view of an outboard motor inaccordance with an embodiment.

FIG. 2 is an enlarged schematic side elevational view of the outboardmotor of FIG. 1 illustrating the configuration of an engine within theoutboard motor.

FIG. 3 is a schematic top plan view illustrating the configuration ofthe engine of the outboard motor of FIG. 1.

FIG. 4 is a schematic front elevational view of the outboard motor ofFIG. 1.

FIG. 5 is a partial sectional and top plan view of a portion of theinduction system of the outboard motor of FIG. 1.

FIG. 6 is a partial schematic sectional and side elevational view of theinduction system of the outboard motor of FIG. 1.

FIG. 7 is a cross-sectional view illustrating an attachment of anelectric component a surge tank of the induction system.

FIG. 8 is a top plan view of an exhaust guide member of the outboardmotor of FIG. 1.

FIG. 9 is an enlarged plan view of a part of the exhaust guide.

FIG. 10 is a cross-sectional view taken along the line X-X of FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The embodiments disclosed herein are described in the context of a smallwatercraft powered by an outboard motor because the embodimentsdisclosed herein have particular utility in this context. However, theembodiments and inventions herein can also be applied to other boatshaving other types of propulsion units as well as other types ofvehicles.

In the following description, the front side of the outboard motor 1 isdefined as hull side, the rear side of the outboard motor 1 indicatesthe side opposite the hull side, and a direction perpendicular to ahorizontal direction is defined as vertical direction.

As shown in FIG. 1, an outboard motor 1 can have a propulsion unit 2having a housing portion consisting of a cowling 3, an upper case 4 anda lower case 5. An engine 10 can be housed in the cowling 3 on the upperside with its crankshaft 10 a extending vertically, and a propeller 6which can be rotatably driven by the engine 10, can be attached to thelower case 5 on the lower side.

The engine 10 can be disposed with the crankshaft 10 a disposed on thehull side of the engine 10 and with its cylinders 10 b on the oppositeside from the hull side. A power transmission mechanism 11 and anexhaust passage (not shown) extending from the engine 10, and so on, canbe housed in the upper case 4 in the middle and the lower case 5. Thepropeller 6 can be rotatably driven by the engine 10 via the powertransmission mechanism 11. The power transmission mechanism 11 can beconstituted of a drive shaft 12, a shift switching mechanism 13, apropeller shaft 14, and other components.

The cowling 3 can be considered as forming an engine room 15. Thecowling 3 can comprise a top cowling 3 a and a bottom cowling 3 b. Aircan be introduced into the engine room 15 through an air intake port 3 a1 for the engine 10 formed through a rear part of the top cowling 3 a.An exhaust guide 16 can be disposed at the upper end of the upper case4, and the engine 10 can be secured to the top surface of the exhaustguide 16.

The bottom cowling 3 b can be secured to an upper periphery of theexhaust guide 16 with bolts. The upper end of the upper case 4 can besecured to a lower periphery of the exhaust guide 16 with bolts. Anapron 17 can be attached to surround an upper part of the upper case 4and the exhaust guide 16. The top cowling 3 a covering the engine 10from above can be openably attached from above to the bottom cowling 3 bsecured to the exhaust guide 16, and removably joined to the bottomcowling 3 b.

The outboard motor 1 can be attached to the rear end of the hull 20. Thehull 20 can have a transom plate 20 a to which a clamp bracket 21 can besecured. A swivel bracket 22 can be rotatably pivoted to the clampbracket 21 by a tilt shaft 23, and the propulsion unit 2 can be pivotedto the swivel bracket 22 for rotation about a steering shaft 24.

As shown in FIG. 2 to FIG. 7, the engine 10 can be a four-cycle V-typeeight-cylinder engine. However, engines having other cylinderconfigurations (e.g., inline, opposed, W), operating on other combustionprinciples (e.g., diesel, 2 stroke, rotary, etc.), and having othernumbers of cylinders can also be used.

The outboard motor 1 can be mounted on the transom plate 20 a forswinging movement between a cruising state in which the crankshaft 10 aextends vertically and a retracted position in which the crankshaft 10 aextends generally horizontally. A crankcase 31 can be joined to thefront mating face of the cylinder block 30 of the engine 10, and acrankcase cover 31 a can be joined to the crankcase 31.

Cylinder heads 32 can be joined to the rear mating faces of the cylinderblock 30, and each of the cylinder heads 32 has a cam chamber sideopening covered with a head cover 33. In the cruising state, the headcovers 33 and the cylinder heads 32 of the engine 10 face backward inthe longitudinal direction of the hull. A flywheel 100 connected to thecrankshaft 10 a can be disposed on the engine 10.

In the cylinder block 30, right and left cylinders 10 b are formed withtheir axes forming a V-bank and extending toward the crankshaft 10 a. Ineach cylinder head 32, intake valve openings 32 a and exhaust valveopenings 32 b are formed for each cylinder, and each of the intake valveopenings 32 a and the exhaust valve openings 32 b can be communicatedwith its corresponding combustion chamber 32 d in the V-bank.

Each of the exhaust valve openings 32 b can be communicated with itscorresponding one of exhaust manifolds 34 through its correspondingexhaust port 32 c extending to the V-bank, and exhaust gas can bedischarged into the water below the engine through exhaust manifolds 34.

Each of the intake valve openings 32 a opens in a side wall of itscorresponding cylinder head 32 through its corresponding intake port 32e. Each of the intake ports 32 e can have an external connecting opening32 f which can be connected to its corresponding one of intake manifolds36. The intake ports 32 e and the intake manifolds 36 can form curvedportions 39 extending forward toward the hull from the intake valveopenings 32 a in a generally arcuate form, and the curved portions 39can be connected to a surge tank 200 to form intake passages A extendingforward.

A throttle body 37 including a throttle valve 37 a can be connected tothe surge tank 200. An intake silencer 38 can be connected to theupstream side of the throttle body 37. The intake silencer 38, which canbe located in front of the engine 10, can be of a size extending almostacross the entire width of the cowling 3 and can have an intake opening38 a through which air can be introduced.

The surge tank 200, which can consist of a first surge tank 200 a andtwo second surge tanks 200 b, can be of a vertically elongated shapecorresponding to the intake manifolds 36 formed by aluminum die-castingand has a prescribed capacity. However, other configurations can also beused.

Each of the intake manifolds 36 connected to the surge tank 200, canhave long intake pipes 36 a and short intake pipes 36 b. The first surgetank 200 a can be located in front, that is, on the hull side, of theengine 10, and the first surge tank 200 a can be communicated with eachof the long intake pipes 36 a. Each of the long intake pipes 36 a can becommunicated with the intake port 32 e of its corresponding cylinder 10b. The intake ports 32 e can be formed on the outside of the cylinderbanks of the V-type engine 10.

The two second surge tanks 200 b can be communicated with the firstsurge tank 200 a and located along the inside, that is, the engine sideof the long intake pipes 36 a. The two second surge tanks 200 b on bothsides of the first surge tank 200 a can be communicated with each otherto ensure a larger capacity. Also, in the V-type engine, the long intakepipes 36 a are located outside the cylinder banks, and dead spaces areformed among the cylinder banks, the crankcase 31 and the long intakepipes 36 a. Thus, the two second surge tanks 200 b extend from thecrankcase cover 31 a to a midportion of the crankcase 31 to ensure thecapacities of the second surge tank 200 b without increasing the size ofthe outboard motor 1.

Each of the short intake pipes 36 b extends into its correspondingsecond surge tank 200 b, and can be located on the inside, that is, theengine side, of an intermediate portion of its corresponding long intakepipe 36 a. Each of the short intake pipes 36 b can also have an opening200 c communicated with the second surge tank 200 b. Each of the shortintake pipes 36 b can also be provided with an on-off valve 201 foropening and closing the short intake pipe 36 b at its opening 200 c tothe long intake pipe 36 a.

The on-off valves 201 can be attached to their corresponding one ofvalve shafts 202 extending vertically, and an actuator 203 can bedisposed at the upper end of each of the valve shafts 202. The valveshafts 202 can be rotated by the actuators 203 to open and close theopenings 200 c with the on-off valves 201.

Since the actuators 203 are located coaxially with the valve shafts 202for the on-off valves 201, the number of parts can be small and thecosts can be reduced. Also, since the actuators 203 can be directlyconnected to the valve shafts 202, the reliability of operation can beimproved.

In some embodiments, the on-off valves 201 are butterfly-type valves andcan be connected to their corresponding valve shafts 202 extending alongthe crankshaft 10 a. Driving motors used as the actuators 203 at theupper ends of the valve shafts 202 can be negative pressure diaphragms,DC motors, stepping motors or the like. Although the actuators 203 arelocated immediately above the on-off valves 201, they can also belocated immediately below the on-off valves 201 and coaxially with thevalve shafts, or other locations.

When the actuators 203 are located immediately above the on-off valves201 as described above, the actuators 203 can be disposed in a deadspace surrounded by the uppermost intake manifold 36, the flywheel 100,and the top cowling 3 a. When the actuators 203 are located immediatelybelow the on-off valves 201, the actuators 203 can be disposed in a deadspace between the lowermost intake manifold 36 and the bottom cowling 3b. In either case, the actuators 203 can be installed without increasingthe external dimensions of the cowling 3.

The engine 10 can be provided with an electric component 300 such as acontroller and an electric auxiliary component 301 including a relay anda fuse. However, other electric devices can also be considered as the“electric component”.

The electric component 300, which can be attached to an upper centralportion of the front wall of the surge tank 200 and located in thecowling 3, can receive detection values from sensors (not shown) such asan engine rotational speed sensor, a hull speed sensor, a throttleopening sensor, an intake pressure sensor, an O2 sensor and so on. Theelectric component 300 can be configured to control the fuel injectionamount, the injection timing and the ignition timing based on thedetection values and according to various operation control mapsincorporated therein. Also, the electric component 300 can be configuredto control the actuators 203 to open and close the openings 200 c withthe on-off valves 201. The electric auxiliary component 301 including arelay and a fuse can be attached to an upper right portion of the frontwall of the surge tank 200 and located in the cowling 3.

By controlling the actuators 203 to open or close the openings 200 cwith the on-off valves 201, for example, to open the on-off valves 201in the high-speed operation range and close the on-off valves 201 in thelow- and intermediate-speed operation range, the intake pipe length canbe selected between a length suitable for low- and intermediate-speedoperation and a length suitable for high-speed operation. In otherwords, an intake pipe length suitable for the operating condition of theengine 10 can be obtained. Therefore, an inertia supercharging effectcan be achieved and target torque characteristics can be obtained in allthe operating ranges of the engine 10.

The open/close control of the on-off valves 201 can be performed basedon the engine rotational speed and the load although it can also dependon the operating range, and the open/close speed of the on-off valves201 can be arbitrarily set depending on the operating range.

Since the second surge tanks 202 are located along the engine side ofthe long intake pipes 36 a as described above, the curvature of the longintake pipes 36 a can be minimum. Also, since the first surge tank 200 alocated on the hull side of the engine 10 has less restrictions in shapethan the intake manifolds 36, the gap between the long intake pipes 36 aand the engine 10 can be used to the maximum extent for the surge tank200 and the distance between the surge tank 200 and the engine 10 can benarrowed. As a result, the outboard motor 1 can be prevented fromincreasing in size.

Also, since the on-off valves 201 for opening and closing the shortintake pipes 36 b can be located on the inside, that is, the engineside, of the long intake pipes 36 a, the actuators 203 for driving theon-off valves 201 can be located on the engine side of the outside ofthe long intake pipes 36 a as viewed in a top plan view. Therefore, itcan be possible to prevent the actuators 203 from protruding to theextent that the outboard motor 1 can be increased in size, and theeffective pipe length of the intake pipes can be changed with a simplestructure without increasing the size of the outboard motor.

Also, as shown in FIG. 5, dead spaces K3 and K4 are formed between thecylinder block 30 of the engine 10 and the right and left long intakepipes 36 a as viewed in a top plan view. A large-size electric component400, such as a starter motor, as an auxiliary component, can be disposedin the dead space K3, and a fuel system component 401 can be disposed inthe dead space K4. Since the dead spaces K3 and K4 between the engine 10and the long intake pipes 36 a are used effectively to dispose auxiliarycomponents, the outboard motor 1 can be prevented from increasing insize.

Fuel injection valves 40 for each cylinder can be inserted into theportions of the cylinder heads 32 corresponding to the intake ports 32e. Each fuel injection valve 40 can have an injection nozzle facing itscorresponding combustion chamber 32 d, and cylindrical fuel supply rails41 which can extend along the crankshaft 10 a, can be located outsidethe cylinder heads 32.

A fuel supply device 50 for supplying fuel to the fuel injection valves40 can be constituted as follows: a fuel filter 57, a low-pressureprimary pump 52 housed in a sealed container 58 for supplying fuel, anda vapor separator 53 can be attached to a front part of a side wall ofthe engine 10.

In the fuel supply device 50, fuel in a fuel tank 55 mounted on the hullcan be supplied to the vapor separator 53 through a low-pressure fuelpipe 54 a, the fuel filter 57, a low-pressure fuel pipe 54 b, and aprimary pump 52 by driving the low-pressure primary pump 52. Excessivefuel discharged from a delivery port 52 a of the primary pump 52 can bereturned to the side of a suction port 52 c of the primary pump 52through a return passage 52 b.

The fuel can be supplied to a high-pressure secondary pump 42 through afuel pipe 56 by driving the primary pump 52 incorporated in the vaporseparator 53. The fuel pressurized by the secondary pump 42 can besupplied to the upper ends of the right and left fuel supply rails 41through a high-pressure fuel pipe 43 and right and left branch hoses 44.Then, while the injection nozzles of the fuel injection valves 40 areopened, the fuel can be injected into the combustion chambers 32 d.Thus, the present fuel injection system can be considered as a “direct”fuel injection system. However, other types of fuel injection systemscan also be used, such as, for example, induction injection systems inwhich fuel is injected into air traveling through the induction systemof the engine.

A canister 60 can be fixedly attached to the vapor separator 53. Thecanister 60 can be made up of a case 60 a directly connected to thevapor separator 53 and filled with an adsorptive activator 60 b such asactivated charcoal. The vapor in the vapor separator 53 flows into thecanister 60, and fuel in the vapor can be adsorbed therein. The airseparated from fuel by adsorption can be discharged into the cowling 3through a discharge pipe 61. The canister 60 can be located below theleft intake manifold 36, and the vapor separator 53 and the canister 60constituting the fuel system component 401 can be disposed in the deadspace K4 formed on the left side of the cylinder block 30 by the V-bankin a compact manner as shown in FIG. 2, FIG. 4 and FIG. 5.

The fuel filter 57 can be located on the opposite side of the cylinderheads 32 with respect to the crankshaft 10 a of the engine 10 in thecowling 3 consisting of the top cowling 3 a and the bottom cowling 3 b.The fuel filter 57 can have a main body 57 a, a cap 57 b and a filter 57c, and the main body 57 a can be fixedly fastened to a bracket 59. Thebracket 59 can be secured to the hull side of the surge tank 200.

The main body 57 a can have a recess with female threads and the cap 57b can have a mounting portion with male threads so that the cap 57 b canbe removably attached to the main body 57 a by a thread structure. Themain body 57 a can have a supply port 57 a 2 and a discharge port 57 a3. The low-pressure fuel pipe 54 a can be connected to the supply port57 a 2 and the low-pressure fuel pipe 54 b can be connected to thedischarge port 57 a 3.

The fuel filter 57 can be covered with at least a heat insulatingmaterial 70. The heat insulating material 70 can have a shape consistentwith the shape of the fuel filter 57. The heat insulating material 70can consist of a plurality of portions. For example, the heat insulatingmaterial 70 can comprise a portion 70 a covering the main body 57 a anda portion 70 b covering the cap 57 b. The heat insulating material 70can be made of a foamed rubber, however, other materials can also beused.

The portion 70 a covering the main body 57 a can be shaped in advanceinto a shape consistent with the external shape of the main body 57 a.Similarly, the portion 70 b covering the cap 57 b can be shaped inadvance into a shape consistent with the external shape of the cap 57 b.

Since the fuel filter 57 can be covered with at least the heatinsulating material 70, the fuel filter 57 can be prevented from beingheated by the engine 10 and the fuel therein can be prevented from beingevaporated. Also, the heat insulating material 70 can have a shapeconsistent with the shape of the fuel filter 57. Since the heatinsulating material 70 can be consistent with the filter shape, a gap isunlikely to be formed between the fuel filter 57 and the heat insulatingmaterial 70. Therefore, heat-insulating efficiency can be improved.

In addition, the heat insulating material 70 can comprise a plurality ofportions and the fuel filter 57 can be covered with the plurality ofportions. Thus, the portion 70 a for the main body 57 a and the portion70 b for the cap 57 b can be easily attached to the main body 57 a andthe cap 57 b, respectively. Also, when the cap 57 b is removed from themain body 57 a to clean the filter 57 c or replace the filter 57 c withnew one, the heat insulating material 70 can be easily attached to thefuel filter 57. Therefore, the fuel filter 57 can be easily assembled,and the work for replacement or maintenance thereof can be improved.

Also, at the time of such maintenance, since the fuel filter 57 can belocated in the hull side of the engine 10 in the cowling 3, a worker caneasily remove the top cowling 3 a from the bottom cowling 3 b and attachthe top cowling 3 a to the bottom cowling 3 b from the hull side.Therefore, the fuel filter 57 can be easily assembled, and the work forreplacement or maintenance of the fuel filter 57 can be improved.

In addition, since the fuel filter 57 can be located on the oppositeside of the cylinder heads 32 with respect to the crankshaft 10 a of theengine 10 in the cowling 3, the fuel filter 57 can be apart from theexhaust manifolds 34 extending from the cylinder heads 32 and preventedfrom being heated more reliably.

In the engine room 15, air X introduced through the air intake port 3 a1 and air Y heated by the engine 10 flow to the intake opening 38 a ofthe intake silencer 38. However, since the fuel filter 57 can be locatedbelow the intake opening 38 a of the engine 10 opening in the cowling 3,where it is not affected by the flow of the air Y, the fuel filter 57can be prevented from being heated.

In some embodiments, at least a part of the fuel pipe 54 can beconnected to the fuel filter 57, that is, the fuel pipes 54 a and 54 bcan also be covered with heat insulating materials 71 and 72,respectively. The fuel pipe 54 a can extend through a front right part 3b 11 of the bottom cowling 3 b into an inner right part of the bottomcowling 3 b, extend in a curve in the vicinity of and below the surgetank 200, can be bent upward from a position below the fuel filter 57,and can be connected to the supply port 57 a 2 from the left side of thefuel filter 57. The fuel pipe 54 b can be connected to the dischargeport 57 a 3 on the right side of the fuel filter 57, extend downwardlyfrom the right side of the fuel filter 57 along the fuel filter 57,extend leftward below the fuel filter 57, and can be connected to theprimary pump 52 housed in the sealed container 58.

As shown in FIG. 2 and FIG. 4, since the low-pressure fuel pipe 54 a forsupplying the fuel in the fuel tank 55 mounted on the hull and thelow-pressure fuel pipe 54 b from the fuel filter 57 to the primary pump52 can be installed around the fuel filter 57 using a dead space K2below the surge tank 200, and since the low-pressure fuel pipe 54 a forsupplying the fuel in the fuel tank 55 mounted on the hull and thelow-pressure fuel pipe 54 b from the fuel filter 57 to the primary pump52 can be covered with the heat insulating materials 71 and 72,respectively, not only the fuel filter 57 but also at least some part ofthe fuel pipe 54 can prevent the fuel therein from being heated. Forexample, the section of the fuel pipe 54 up to the low-pressure primarypump 52 can be covered with the heat insulating materials 71 and 72.Since a negative pressure can be produced and the fuel tends to beevaporated in the fuel pipes 54 a and 54 b as well as in the fuel filter57 when the low-pressure primary pump 52 is driven, the heat insulatingmaterials 71 and 72 covering the fuel pipes 54 a and 54 b prevent thefuel therein from being heated more reliably.

The heat insulating materials 71 and 72, as well as the heat insulatingmaterial 70, can be made of a foamed rubber, although other materialscan also be used. Although water is likely to enter the cowling 3, evenif water enters, their heat insulating properties and durability are notdeteriorated. In addition, the heat insulating materials 70, 71 and 72can be produced inexpensively and can be easily attached. Therefore, theheat insulating materials 70, 71 and 72 can be easily assembled, and thework for replacement or maintenance thereof can be improved.

Referring next to FIG. 2 to FIG. 4 and FIG. 7, the attachment of anelectric component E is described in greater detail. In the outboardmotor 1, an electric component 300 such as a controller including an ICintegrated circuit, resistors, a printed circuit board, memory devices,processors, and so on, is shown as the electric component E. However,the electric component E is not limited thereto and may include electricauxiliary components such as a relay and a fuse or any other electricdevice. The electric component E can be housed in an electric componentbox 500. The electric component box 500 can comprise a box body 500 aand a lid 500 b. Mounting portions 500 a 1 and 500 b 1 formedrespectively thereon can be removably fastened with screws 500 c. Theelectric component E can be supported by and attached to mounting bosses500 a 2 in the box body 500 a.

The surge tank 200 can be made of aluminum, and formed by, for example,aluminum die-casting. Since the surge tank 200 can be made of aluminum,the surge tank 200 can be strong and lightweight.

The surge tank 200 can have four mounting portions 200 f for theelectric component E formed integrally therewith at top and bottom ofboth sides. The box body 500 a can have grommets 501 at positionscorresponding to the mounting portions 200 f. The box body 500 a can befixed by fastening bolts 502 with the grommets 501 placed on themounting portions 200 f. Therefore, the electric component E can beattached by first attaching the box body 500 a, to which the electriccomponent E has been attached, to the surge tank 200 and then attachingthe lid 500 b to the box body 500 a.

As described above, the surge tank 200 can be located on the hull sideof the engine 10 in the cowling 3, and the electric component E can beattached to the front side of the surge tank 200. Since the surge tank200 has the mounting portions 200 f for the electric component E formedintegrally therewith, there is no need for a mounting stay or the like.Therefore, the number of parts can be reduced and the number of assemblysteps can be reduced.

Also, the fuel filter 57 can be located in front of, that is, on thehull side of the electric component box 500. Since the fuel filter 57can be located in front of the electric component E as described above,the fuel filter 57 can be located apart from the engine 10 to preventthe fuel therein from being heated. In addition, maintenance of the fuelfilter 57 can be carried out easily without interference of the electriccomponent E.

In addition, since the electric component E can be housed in theelectric component box 500, it is only necessary to attach the electriccomponent box 500 to the surge tank 200. Therefore, the number of themounting portions can be minimized and the work efficiency can beimproved.

Since the electric component E can be attached by fixedly securing theelectric component box 500 only on the front side of the surge tank 200as described above, the surge tank 200 can be connected to the intakemanifolds 36 after the electric component E has been attached to thesurge tank 200. Therefore, the flexibility in assembly can be improved.Also, since the intake manifolds 36 can be removed from the surge tank200 with the electric component E attached to the surge tank 200, themaintainability can be high.

In addition, since the surge tank 200 can be located between theelectric component E and the engine 10, the influence of the heat fromthe engine 10 on the electric component E can be reduced. Also, sincethe front side of the surge tank 200 faces the hull, when the topcowling 3 a of the cowling 3 is removed from the bottom cowling 3 b formaintenance of the electric component E, the worker can easily reach theelectric component E from the hull side. Therefore, the maintainabilitycan be improved.

Referring next to FIG. 8 to FIG. 10, the constitution of the exhaustguide 16 of the outboard motor 1 is described. In some embodiments, apair of right and left dampers 601 can be provided in a mount bracket600, and fixing bolts 602 can be inserted through the paired right andleft dampers 601. The mount bracket 600 can be located at the center ina space surrounded by a guide rib 16 a of the exhaust guide 16. A mountcover 610 can be used to cover the mount bracket 600 from above and canbe fixedly secured with four fixing bolts 611.

The fixing bolts 602 can extend through the swivel bracket 22 viacollars 612, and can be fixedly fastened with nuts 613. The exhaustguide 16 can be thereby secured to the swivel bracket 22, making thepropulsion unit 2 rotatable about the steering shaft 24.

The exhaust guide 16 can have a drive shaft through hole 16 b in frontof the mount cover 610 and a pair of right and left exhaust passages 16c behind the mount cover 610, that is, on the other side of the driveshaft through hole 16 b with respect to the guide rib 16 a.

The mount cover 610 can have a pawl 610 a extending toward an exhaustpassages 16 c side portion 16 a 1 of the guide rib 16 a, and a damper630 can be interposed between the mount cover 610 and the exhaustpassages 16 c side portion 16 a 1 of the guide rib 16 a. The damper 630can be made of a rubber material or the like, although other materialscan also be used. The damper 630 can also have a laterally extendingportion 630 a facing heads 602 a of the fixing bolts 602, a backwardlyextending portion 630 b engaged with a recess 16 a 2 of the guide rib 16a, and a forwardly extending portion 630 c engaged with a lower side ofthe pawl 610 a of the mount cover 610.

When the backwardly extending portion 630 b is engaged with the recess16 a 2 of the guide rib 16 a and the forwardly extending portion 630 cis engaged with a lower side of the pawl 610 a of the mount cover 610,the damper 630 can be fixed with the laterally extending portion 630 afacing the heads 602 a of the fixing bolts 602.

Even if the paired right and left dampers 601 of the mount bracket 600are displaced largely when the outboard motor 1 is driven in reverse orhit some driftwood, the heads 602 a of the paired right and left fixingbolts 602 abut against the laterally extending portion 630 a of thedamper 630 to protect the guide rib 16 a of the exhaust guide 16 andprevent generation of unpleasant noise.

As described above, when the damper 630 is inserted between the guiderib 16 a and the mount cover 610 with the backwardly extending portion630 b engaged with the recess 16 a 2 of the guide rib 16 a and theforwardly extending portion 630 c engaged with a lower side of the pawl610 a of the mount cover 610, the laterally extending portion 630 afaces the heads 602 a of the fixing bolts 602 and the damper 630 can beattached easily. Also, the forwardly extending portion 630 c of thedamper 630 can be engaged with a lower side of the pawl 610 a of themount cover 610 and can be prevented from coming off upwardly, and thebackwardly extending portion 630 b can be engaged with the recess 16 a 2of the guide rib 16 a to prevent the damper 630 from moving laterally.In addition, since the damper 630 has the laterally extending portion630 a formed integrally therewith and facing the heads 602 a of thefixing bolt 602, the number of parts can be reduced.

The present inventions are applicable to outboard motors in which anengine is disposed in an upright position so that the crankshaft thereofextends generally vertically during cruising, and allows an electriccomponent to be attached easily with a simple structure.

Although these inventions have been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present inventions extend beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the inventions and obvious modifications and equivalentsthereof. In addition, while several variations of the inventions havebeen shown and described in detail, other modifications, which arewithin the scope of these inventions, will be readily apparent to thoseof skill in the art based upon this disclosure. It is also contemplatedthat various combination or sub-combinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the inventions. It should be understood that various featuresand aspects of the disclosed embodiments can be combined with orsubstituted for one another in order to form varying modes of thedisclosed inventions. Thus, it is intended that the scope of at leastsome of the present inventions herein disclosed should not be limited bythe particular disclosed embodiments described above.

PRIORITY INFORMATION

This application is based on and claims priority to Japanese PatentApplication No. 2006-114817, filed Apr. 18, 2006, the entire contents ofwhich is hereby expressly incorporated by reference.

1. An outboard motor comprising a cowling, an engine disposed in anupright position in the cowling such that a crankshaft of the enginethereof extends generally vertically during cruising, a surge tanklocated on the hull side of the engine in the cowling, and a mountingportion for an electric component provided on a front face of the surgetank.
 2. The outboard motor according to claim 1, wherein the mountingportion for the electric component is formed integrally with the surgetank.
 3. The outboard motor according to claim 1, wherein the surge tankis made of aluminum.
 4. The outboard motor according to claim 2, whereinthe surge tank is made of aluminum.
 5. The outboard motor according toclaim 1 additionally comprising an electric component box, the electriccomponent being housed in the electric component box.
 6. The outboardmotor according to claim 2 additionally comprising an electric componentbox, the electric component being housed in the electric component box.7. The outboard motor according to claim 3 additionally comprising anelectric component box, the electric component being housed in theelectric component box.
 8. The outboard motor according to claim 1additionally comprising a fuel filter, the fuel filter being located infront of the electric component.
 9. The outboard motor according toclaim 2 additionally comprising a fuel filter, the fuel filter beinglocated in front of the electric component.
 10. The outboard motoraccording to claim 3 additionally comprising a fuel filter, the fuelfilter being located in front of the electric component.
 11. Theoutboard motor according to claim 5 additionally comprising a fuelfilter, the fuel filter being located in front of the electriccomponent.
 12. An outboard motor comprising a cowling, an enginedisposed in the cowling, a surge tank located on the hull side of theengine in the cowling, and a mounting portion configured to connect withan electric component provided on a front face of the surge tank. 13.The outboard motor according to claim 12, wherein the mounting portionfor the electric component is formed integrally with the surge tank. 14.The outboard motor according to claim 12 additionally comprising anelectric component box, the electric component being housed in theelectric component box, and the mounting portion being configured toconnect with the electric component box.
 15. The outboard motoraccording to claim 12 additionally comprising a fuel filter, the fuelfilter being located in front of the electric component.